Tokyo has demanded Seoul stop using the term "sex slaves" when referring to the "comfort women," Japan's euphemistic term for the tens of thousands of females who were forced to provide sex for Japanese troops before and during the war, sources close to Japan-South Korean relations said Saturday.

South Korea rejected the demand, made in bilateral working-level negotiations on resolving the long-standing issue, the sources said.

In the negotiations, Japan has also demanded the removal of a statue in front of the Japanese Embassy in Seoul of a girl that symbolizes the issue, the sources said. Tokyo also wants Seoul to stop meddling in the activities of private groups speaking ill of Japan abroad, they added.